1. Field of the Invention
The present invention relates generally to semiconductor thermography and more specifically to a system and method for measuring the thermal behavior of integrated circuits.
2. Description of Related Art
The present invention references Applicant's U.S. Pat. No. 6,064,810 (the “'810 patent”), the contents of which are incorporated herein by reference.
As semiconductor devices become physically more complex with shrinking feature sizes and higher local power densities, cooling problems multiply, which can lead to a decrease in performance and reliability. Thus, understanding and determining the thermal behavior of modern electronics has become a key issue in their design. As a result, there is a critical demand for methods that can be used to determine the temperature of features at the submicron level, particularly when most important features are physically inaccessible. Computational approaches can provide insight into the internal thermal behavior of such complex devices, but can be limited by the inherent necessity of modeling the heat sources, which in the case of self-heating microelectronic devices, are the result of electrical fields whose exact shapes and locations are difficult to specify with reasonable certainty. Moreover, such devices can actually experience irreversible changes in thermo-physical properties and/or geometries that cannot be otherwise predicted from theory or monitored. Experimental approaches can also be helpful in determining thermal behavior, but require either physical access or a visual path to the region of interest. Contact methods, for example, present the difficulties of having to access features of interest with an external probe, or in the case of embedded features, fabricate a measuring probe into the device, and then having to isolate and exclude the influence of the probe itself. Non-contact methods, on the other hand, can provide surface temperature profiles, but in and of themselves cannot impart information on internal behavior. In other words, these methods provide a two-dimensional perspective on what otherwise is, in the case of stacked complex devices, an intricate three-dimensional thermal behavior.
Therefore, a need exists for an improved and more comprehensive method of conducting three-dimensional thermal characterization of semiconductor devices with shrinking characteristics and higher operating speeds. Further, a need exists for a non-invasive method of conducting thermal characterization that accurately measures the thermal characteristics without imparting its own energy into the system. Further, a need exists for a method of conducting thermal characterization in situ and at the sub-micron level of today's devices.